#include <stdio.h>

/* START: fig10_43.txt */
double Eval(int N) {
	int i;
	double Sum;

	if (N == 0)
		return 1.0;
	else {
		Sum = 0.0;
		for (i = 0; i < N; i++)
			Sum += Eval(i);
		return 2.0 * Sum / N + N;
	}
}
/* END */

main() {
	printf("%f\n", Eval(10));
	return 0;
}
